The present invention relates to a charging device for rechargeable batteries of any size, voltage and capacity.
Charging devices for rechargeable storage batteries are known in various forms. (Although the term "storage batteries" is used herein, it is to be interpreted as meaning any type of rechargeable battery.) They are used for charging suitable storage batteries repeatedly and include a broad spectrum of devices in order to charge different kinds of storage batteries as exemplified by heavy vehicle batteries down to the smallest button cell.
Recently, charging devices for storage batteries are being used to a greater extent because more and more battery-operated devices are being used. Such batteries are used not only in the domestic area (rechargeable toothbrushes, flashlights, etc.), but also in the handicraft and industrial sectors, especially also for electric tools. To avoid the need for being connected to an electrical network, electric tools have a storage battery pack or some other power supply equipment which makes them independent of such a network.
Such storage battery packs, as well as the nickel-cadmium storage batteries which are already being used frequently at the present time, are obtainable in the common battery sizes and can, in some cases, withstand more than 1,000 charging cycles. They are preferred over regular batteries not only for environmental reasons, but also because they can provide high currents for long periods of time for driving motors.
Until now, practically any device which is used in the household, the trade or the industry and obtains its power from storage batteries, has at its disposal its own, specially matched charger. Such a charger is designed so that many hours of charging time are required before the device can be used again.
Such chargers usually have all of the equipment required for charging the storage battery or batteries satisfactorily. Such equipment includes transformers, rectifier circuits, control systems, temperature sensors to avoid overheating the storage battery during the charging, etc. However, such equipment is not suitable for use with storage battery packs or rechargeable batteries of a different size and/or different capacity that usually also have a different type of connector. This not only leads to inconvenience when the various devices driven by storage batteries are used, but also to undesirable investments in inventory and extensive inventory storage requirements.
Universal chargers for rechargeable batteries are known, particularly if they are of a size for charging conventional monocells or baby cells. Such chargers have several possible positions, perhaps being adjustable by spring tension. However, these chargers, which have not been matched to the batteries, generate only a particular, low charging current and cannot take the state of the battery into consideration nor determine, for example, the temperature of the battery.
It is desired to provide an integrated, yet universally applicable storage battery charging system in modular construction so that rechargeable storage batteries of any size, voltage and capacity may be recharged within a very short time if desired.